Magnetic tunnel junction device and method for manufacturing the same

ABSTRACT

The present invention relates to a magnetic tunnel junction device and a manufacturing method thereof. The magnetic tunnel junction device includes: i) a first magnetic layer including a compound having a chemical formula of (A 100-x B x ) 100-y C y ; ii) an insulating layer deposited on the first magnetic layer; and iii) a second magnetic layer deposited on the insulating layer and including a compound having a chemical formula of (A 100-x B x ) 100-y C y . The first and second magnetic layers have perpendicular magnetic anisotropy, A and B are respectively metal elements, and C is at least one amorphizing element selected from a group consisting of boron (B), carbon (C), tantalum (Ta), and hafnium (Hf).

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2009-0077492 filed in the Korean IntellectualProperty Office on Aug. 21, 2009, the total contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a magnetic tunnel junction device and amethod for manufacturing the same. More particularly, it relates to amagnetic tunnel junction device using an amorphous material withperpendicular magnetic anisotropy, and a method of manufacturing thesame.

(b) Description of the Related Art

Recently, various types of memories have been developed. For example, amagnetic random access memory (MRAM), a phase-change random accessmemory (PRAM), and a resistive random access memory (RRAM) have beendeveloped.

The MRAM uses a magnetic tunnel junction (MJT) element as a data storageelement. The magnetic tunnel junction element included in a memory cellis based on ferromagnetic tunnel junction properties. The magnetictunnel junction element consists of two magnetic layers separated by aninsulating layer, and the current flows in the insulating layer throughthe tunneling mechanism. Here, when the relative magnetizationdirections of the two magnetic layers are parallel to each other, themagnetic tunnel junction element has low resistance. In contrast, whenthe two magnetic layers have an antiparallel magnetizationconfiguration, the magnetic tunnel junction element has high resistance.The low resistance and the high resistance indicate digital data,respectively, corresponding to 0 and 1.

Thermal stability is defined as the ability of retaining the digitaldata for a long period of time. The thermal stability is proportional toanisotropy energy of the magnetic layer of the magnetic tunnel junctionelement. In the majority of cases, the ferromagnetic materials used inthe magnetic tunnel junction element have an in-plane magneticanisotropy, for example, represented by shape anisotropy energy, andtherefore the total anisotropy energy is small. In order to solve thisproblem, a ferromagnetic material with perpendicular magneticanisotropy, for example, represented by high crystalline anisotropyenergy, is used as a material of the magnetic tunnel junction element.Accordingly, the total anisotropy energy of the magnetic tunnel junctiondevice is large so that the magnetic tunnel junction device can havesuperior thermal stability with a small volume.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the invention andtherefore it may contain information that does not form the prior artthat is already known in this country to a person of ordinary skill inthe art.

SUMMARY OF THE INVENTION

The present invention has been made in an effort to provide a magnetictunnel junction device having advantages of increasing a read signalvalue and improving thermal stability. In addition, the presentinvention provides a manufacturing method of the magnetic tunneljunction device.

A magnetic tunnel junction device according to an exemplary embodimentof the present invention includes: i) a first magnetic layer including acompound having a chemical formula of (A_(100-x)B_(x))_(100-y)C_(y); ii)an insulating layer deposited on the first magnetic layer; and iii) asecond magnetic layer deposited on the insulating layer and including acompound having a chemical formula of (A_(100-x)B_(x))_(100-y)C_(y). Thefirst and second magnetic layers have perpendicular magnetic anisotropy,and A and B are metal elements and C is at least one amorphizing elementselected from a group consisting of boron (B), carbon (C), tantalum(Ta), and hafnium (Hf).

A may be at least one element selected from a group consisting of iron(Fe), cobalt (Co), nickel (Ni), manganese (Mn), and chrome (Cr). B maybe at least one element selected from a group consisting of platinum(Pt), palladium (Pd), rhodium (Rh), gold (Au), mercury (Hg), andaluminum (Al). The insulating layer includes a compound having achemical formula of D_(100-z)E_(z), and D may be at least one elementselected from a group consisting of lithium (Li), beryllium (Be), sodium(Na), magnesium (Mg), niobium (Nb), titanium (Ti), vanadium (V),tantalum (Ta), barium (Ba), palladium (Pd), zirconium (Zr), holmium(Ho), potassium (K), and silver (Ag), and E is at least one elementselected from a group consisting of oxygen (O), nitrogen (N), carbon(C), hydrogen (H), selenium (Se), chlorine (Cl), and fluorine (F). Atleast one of the first and second magnetic layers may have a cubic ortetragonal structure.

The magnetic tunnel junction device according to the exemplaryembodiment of the present invention may further include i) a firstin-plane magnetic layer with in-plane magnetic anisotropy depositedbetween the second magnetic layer and the insulating layer and ii) afirst seed layer, for inducing the formation of crystalline structure,deposited on the second magnetic layer. The first in-plane magneticlayer with in-plane magnetic anisotropy may include at least one elementselected from a group consisting of Fe, CoFe, and CoFeB. When thecompound included at least one of the first and second perpendicularmagnetic layers has a chemical formula of(Fe_(100-x)Pd_(x))_(100-x)B_(x) or (Fe_(100-x)Pt_(x))_(100-x)B_(x), thefirst seed layer for inducing the formation of crystalline structure mayinclude at least one element selected from a group consisting of Pd, Pt,Au, and Fe. The magnetic tunnel junction device according to theexemplary embodiment of the present invention may further include i) asecond in-plane magnetic layer with in-plane magnetic anisotropydeposited between the first magnetic layer and the insulating layer andii) a second seed layer, for inducing the formation of crystallinestructure, deposited under the first magnetic layer.

A magnetic tunnel junction device according to another exemplaryembodiment of the present invention includes: i) a seed layer forinducing the formation of crystalline structure; ii) a perpendicularmagnetic layer with perpendicular magnetic anisotropy deposited on theseed layer and including a compound having a chemical formula of(A_(100-x)B_(x))_(100-y)C_(y); iii) an in-plane magnetic layer within-plane magnetic anisotropy deposited on the perpendicular magneticlayer; iv) an insulating layer deposited on the in-plane magnetic layer;v) an in-plane magnetic anisotropic layer deposited on the insulatinglayer; and vi) a perpendicular magnetic layer with perpendicularmagnetic anisotropy deposited on the in-plane magnetic layer. A may beat least one element selected from a group consisting of iron (Fe),cobalt (Co), nickel (Ni), manganese (Mn), and chrome (Cr), B is at leastone element selected from a group consisting of platinum (Pt), palladium(Pd), rhodium (Rh), gold (Au), mercury (Hg), and aluminum (Al), and C isat least one element selected from a group consisting of boron (B),carbon (C), tantalum (Ta), and hafnium (Hf).

A manufacturing method of a magnetic tunnel junction device according toanother exemplary embodiment of the present invention includes: i)providing a first magnetic layer including an amorphizing element; ii)providing an insulating layer on the first magnetic layer; iii)providing a second magnetic layer including an amorphizing element onthe insulating layer; and iv) crystallizing the first and secondmagnetic layers by performing annealing on the first magnetic layer, theinsulating layer, and the second magnetic layer.

In the providing of the first magnetic layer and in the providing of thesecond magnetic layer, the first and second magnetic layers mayrespectively include a compound having a chemical formula of(A_(100-x)B_(x))_(100-y)C_(y), and A may be at least one elementselected from a consisting of iron (Fe), cobalt (Co), nickel (Ni),manganese (Mn), and chrome (Cr), B may be at least one element selectedfrom a group consisting of platinum (Pt), palladium (Pd), rhodium (Rh),gold (Au), mercury (Hg), and aluminum (Al), and C may be at least oneamorphizing element selected from a group consisting of boron (B),carbon (C), tantalum (Ta), and hafnium (Hf). In the crystallizing of thefirst and second magnetic layers, the first and second magnetic layersmay have perpendicular magnetic anisotropy. In the crystallizing of thefirst and second magnetic layers, the annealing may be performed on thefirst magnetic layer, the insulating layer, and the second magneticlayer at 300° C. to 600° C.

The manufacturing method according to the other exemplary embodiment ofthe present invention may further include i) providing an in-planemagnetic layer with in-plane magnetic anisotropy between the secondmagnetic layer and the insulating layer and ii) providing a seed layer,for inducing the formation of crystalline structure, on the secondmagnetic layer. The manufacturing method according to the otherexemplary embodiment of the present invention may further include i)providing another in-plane magnetic layer with in-plane magneticanisotropy between the first magnetic layer and the insulating layer andii) providing a seed layer, for inducing the formation of crystallinestructure, under the first magnetic layer.

A manufacturing method of a magnetic tunnel junction device according toanother exemplary embodiment of the present invention includes: i)providing a seed layer for inducing the formation of crystallinestructure; ii) providing a magnetic layer including a compound having achemical formula of (A_(100-x)B_(X))_(100-y)C_(y) on the seed layer;iii) providing a first in-plane magnetic layer with in-plane magneticanisotropy on the magnetic layer; iv) providing an insulating layer onthe first in-plane magnetic layer; v) providing a second in-planemagnetic layer with in-plane magnetic anisotropy on the insulatinglayer; vi) providing a perpendicular magnetic layer with perpendicularmagnetic anisotropy on the second in-plane magnetic layer; and vii)crystallizing the magnetic layer by performing annealing on the seedlayer, the magnetic layer, the first in-plane magnetic layer within-plane magnetic anisotropy, the insulating layer, the second in-planemagnetic layer with in-plane magnetic anisotropy, and the perpendicularmagnetic layer with perpendicular magnetic anisotropy,

In the crystallizing of the magnetic layer, the magnetic layer may haveperpendicular magnetic anisotropy and may include a compound having achemical formula of (A_(100-x)B_(x))_(100-y)C_(y) in which A may be atleast one element selected from a group consisting of iron (Fe), cobalt(Co), nickel (Ni), manganese (Mn), and chrome (Cr), B may be at leastone element selected from a group consisting of platinum (Pt), palladium(Pd), rhodium (Rh), gold (Au), mercury (Hg), and aluminum (Al), and Cmay be at least one amorphizing element selected from a group consistingof boron (B), carbon (C), tantalum (Ta), and hafnium (Hf).

According to the present invention, the insulating layer is deposited onthe amorphous magnetic layer so that the insulating layer is depositedwith low roughness. Accordingly, the magnetic tunnel junction devicehaving a high read signal value can be manufactured. In addition, acrystal structure of the amorphous magnetic layer is recovered throughannealing so that it has perpendicular magnetic anisotropy. Accordingly,the magnetic tunnel junction device having higher thermal stability canbe manufactured. As a result, the read signal value and thermalstability of the magnetic tunnel junction device can be increased sothat the magnetic tunnel junction device can be used in a magneticrandom access memory (MRAM) or a high frequency oscillator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows a cross-sectional view of a magnetic tunneljunction device according to a first exemplary embodiment of the presentinvention.

FIG. 2 schematically shows a flowchart of a manufacturing method of themagnetic tunnel junction device of FIG. 1.

FIG. 3 schematically shows a magnetic tunnel junction device formed of asequentially stacked first magnetic layer, insulating layer, and secondmagnetic layer before annealing.

FIG. 4 schematically shows a cross-sectional view of a magnetic tunneljunction device according to a second exemplary embodiment of thepresent invention.

FIG. 5 schematically shows a cross-sectional view of a magnetic tunneljunction device according to a third exemplary embodiment of the presentinvention.

FIG. 6 is an X-ray diffraction graph of a magnetic tunnel junctiondevice manufactured according to a first experimental example.

FIG. 7 is a magnetic hysteresis curve of a magnetic layer of a magnetictunnel junction device manufactured according to a second experimentalexample before annealing and after annealing.

DETAILED DESCRIPTION OF THE EMBODIMENTS

It will be understood that when an element is referred to as being “on”another element, it can be directly on another element or interveningelements may be present therebetween. In contrast, when an element isreferred to as being “directly on” another element, there are nointervening elements therebetween.

It will be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, components,regions, layers, and/or sections, they are not limited thereto. Theseterms are only used to distinguish one element, component, region,layer, or section from another element, component, region, layer, orsection. Thus, a first element, component, region, layer, or sectiondiscussed below could be termed a second element, component, region,layer, or section without departing from the teachings of the presentinvention.

Terminologies used herein are provided to merely mention specificexemplary embodiments and are not intended to limit the presentinvention. Singular expressions used herein include plurals unless theyhave definitely opposite meanings. The meaning of “including” used inthis specification gives shape to specific characteristics, regions,positive numbers, steps, operations, elements, and/or components, and donot exclude the existence or addition of other specific characteristics,regions, positive numbers, steps, operations, elements, components,and/or groups.

Spatially relative terms, such as “below” and “above” and the like, maybe used herein for ease of description to describe one element orfeature's relationship to another element(s) or feature(s) asillustrated in the figures. It will be understood that spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe drawings. For example, if the device in the figures is turned over,elements described as “below” other elements or features would then beoriented “above” the other elements or features. Thus, the exemplaryterm “below” can encompass both an orientation of above and below.Apparatuses may be otherwise rotated 90 degrees or at other angles, andthe spatially relative descriptors used herein are then interpretedaccordingly.

All the terminologies including technical terms and scientific termsused herein have the same meanings that those skilled in the artgenerally understand Terms defined in dictionaries are construed to havemeanings corresponding to related technical documents and the presentdescription, and they are not construed as ideal or very officialmeanings, if not defined.

Exemplary embodiments of the present invention described with referenceto cross-sectional views represent ideal exemplary embodiments of thepresent invention in detail. Therefore, various modification ofdiagrams, for example, modifications of manufacturing methods and/orspecifications, are expected. Accordingly, exemplary embodiments are notlimited to specific shapes of shown regions, and for example, alsoinclude modifications of the shape by manufacturing. For example,regions shown or described as smooth may generally have rough or roughand nonlinear characteristics. Further, portions shown to have sharpangles may be rounded. Therefore, the regions shown in the drawings arebasically just schematic and the shapes thereof are not intended to showthe exact shapes of the region and are also not intended to reduce thescope of the present invention.

In the specification, the term “roughness” implies an index indicatingheight deviation of thin film interface in a perpendicular direction. Ifthe roughness is low, the height of interface is constant, that is, theinterface is smooth. By contrast, if the roughness is high, the heightdeviation of interface is large, that is, the interface is rugged. Inorder to increase a read signal of an element, it is preferably to forma smooth interface by decreasing the roughness of an insulating layer.

FIG. 1 schematically shows a cross-sectional structure of a magnetictunnel junction device 100 according to a first exemplary embodiment ofthe present invention. The cross-sectional structure of the magnetictunnel junction device 100 shown in FIG. 1 is an example of the presentinvention, and the present invention is not limited thereto. That is,the cross-sectional structure of the magnetic tunnel junction device 100can be modified in various shapes.

As shown in FIG. 1, the magnetic tunnel junction device 100 includes afirst magnetic layer 10, an insulating layer 20, and a second magneticlayer 30. The first magnetic layer 10 functions as a fixed magneticlayer, and the second magnetic layer 30 functions as a free magneticlayer. In order to increase thermal stability of the magnetic tunneljunction device 100, the first and second magnetic layers 10 and 20 areformed of a ferromagnetic material having perpendicular magneticanisotropy when an ordered crystal structure such as an L1₀ based alloyis recovered.

The first magnetic layer 10 and the second magnetic layer 30respectively include a material having a chemical formula of(A_(100-x)B_(x))_(100-y)C_(y). Here, A and B may respectively be metalelements. In further detail, A may be iron (Fe), cobalt (Co), nickel(Ni), manganese (Mn), or chrome (Cr). In addition, B may be platinum(Pt), palladium (Pd), rhodium (Rh), gold (Au), mercury (Hg), or aluminum(Al). Further, C may be boron (B), carbon (C), tantalum (Ta), andhafnium (Hf).

An alloy having a chemical formula of A_(100-x)B_(x) has an orderedstructure. The ordered structure may be a cubic structure or atetragonal structure. The cubic structure may exemplarily include acrystal structure of an L1₂ type. In addition, the tetragon structuremay exemplarily include a crystal structure of L1₀. Before annealing, Cis added for the amorphization of an alloy having a chemical formula ofA_(100-x)B_(x). The first magnetic layer 10 and the second magneticlayer 30 may be respectively formed of different materials or the samematerial.

The insulating layer 20 includes a compound having a chemical formula ofD_(100-z)E_(z). Here, D is at least one element selected from a groupconsisting of lithium (Li), beryllium (Be), sodium (Na), magnesium (Mg),niobium (Nb), titanium (Ti), vanadium (V), tantalum (Ta), barium (Ba),palladium (Pd), zirconium (Zr), holmium (Ho), potassium (K), and silver(Ag), and E is at least one element selected from a group consisting ofoxygen (O), nitrogen (N), carbon (C), hydrogen (H), selenium (Se),chlorine (Cl), and fluorine (F). For example, the insulating layer 20may be made of magnesium oxide (MgO).

The insulating layer 20 may have a cubic structure. The cubic structuremay exemplarily include a crystal structure of a B1 type. The insulatinglayer may have a (001) orientation along a direction that isperpendicular to a substrate surface of a thin film interface forincreasing a read signal value of the magnetic tunnel junction device100.

As shown by the arrow of FIG. 1, the first magnetic layer 10 and thesecond magnetic layer 30 have perpendicular magnetic anisotropy afterrecovering their crystal structures through annealing. Accordingly, themagnetic tunnel junction device 100 having excellent thermal stabilityand a high read-signal value can be manufactured. Hereinafter, amanufacturing method of the magnetic tunnel junction device 100 of FIG.1 will be described in further detail with reference to FIG. 2 and FIG.3.

FIG. 2 schematically shows a flowchart of a manufacturing method of themagnetic tunnel junction device 100 of FIG. 1.

As shown in FIG. 2, the manufacturing method of the magnetic tunneljunction device 100 includes: i) providing the first magnetic layer 10of FIG. 1 (S10); ii) providing the insulating layer 20 of FIG. 1 on thefirst magnetic layer 10 (S20); iii) providing the second magnetic layer30 on the insulating layer 20 (S30); and annealing the first magneticlayer 10, the insulating layer 20, and the second magnetic layer 30(S40). The manufacturing method of the magnetic tunnel junction device100 may further include other steps.

In the step S10, the first magnetic layer 10 is provided formanufacturing the magnetic tunnel junction device 100. The firstmagnetic layer 10 may be formed by a deposition method. Theferromagnetic material 10 has a perpendicular magnetic anisotropy whenit has an ordered crystal structure. However, the first magnetic layer10 is deposited with adding an amorphizing element to the originalferromagnetic material. Therefore, during the deposition process, thefirst magnetic layer 10 does not have perpendicular magnetic anisotropy.The first magnetic layer 10 has the perpendicular magnetic anisotropywhen its ordered crystal structure is recovered through the annealing ofS40.

In the case that the first magnetic layer 10 has a crystal structure, acrystal lattice constant of the magnetic layer 10 may be quite differentfrom that of the insulating layer 20. In this case, the insulating layer20 having a (001) orientation is difficult to grow on the first magneticlayer 10. In addition, although the insulating layer 20 having the (001)orientation grows on the insulating layer 20, the roughness of theinsulating layer 20 is increased because the insulating layer 20 isquite different from the first magnetic layer 10 in crystal latticeconstant. Particularly, a lattice constant of an alloy ordered in thetype of L1₀ having strong perpendicular magnetic anisotropy is quitedifferent from that of magnesium oxide which is used as a material ofthe insulating layer 20. Therefore, it is difficult to grow magnesiumoxide on the L1₀-structure alloy with the (001) texture of a crystalstructure of B1. Furthermore, although magnesium oxide can be grown onthe L1₀-structure alloy, the roughness of the insulating layer 20 isincreased due to a large difference in lattice constant therebetween,thereby causing a decrease of the read signal value of the magnetictunnel junction device 100.

However, the first magnetic layer 10 according to the first exemplaryembodiment of the present invention is deposited in amorphous state sothat the insulating layer 20 is grown well with the (001) orientation onthe first magnetic layer 10. In addition, a crystal structure does notexist in the amorphous first magnetic layer 10. Thus, the first magneticlayer 10 and the insulating layer 20 do not have a crystal structuredifference so that the roughness of the insulating layer 20 isdecreased. Accordingly, the read signal value of the magnetic tunneljunction device 100 can be greatly increased, and the resistance of themagnetic tunnel junction device 100 can be significantly improved.

In the step S20, the insulating layer 20 is formed on the first magneticlayer 10. That is, the insulating layer 20 is deposited with the (001)texture on the first magnetic layer 10. In addition, the roughness ofthe insulating layer 20 is decreased.

In the step S30, the second magnetic layer 30 is formed on theinsulating layer 20. The second magnetic layer 30 is deposited inamorphous state. The second magnetic layer 30 can be manufactured byusing the same method as that of the first magnetic layer 10 of the stepS10.

FIG. 3 schematically shows a sequentially stacked first magnetic layer10, insulating layer 20, and second magnetic layer 30 of the magnetictunnel junction device before annealing.

Since the first magnetic layer 10 and the second magnetic layer 30formed with the amorphous phase does not have a crystal structure beforethe annealing is performed on the magnetic tunnel junction device, thefirst and second magnetic layers 10 and 30 do not have perpendicularmagnetic anisotropy. Thus, as shown in FIG. 3, the magnetized moments ofthe first and second magnetic layers 10 and 30 are formed along thex-axis direction, that is, the in-plane direction.

Referring back to FIG. 2, the first magnetic layer 10, the insulatinglayer 20, and the second magnetic layer 30 manufactured through theabove-described method are annealed in the step S40. While the firstmagnetic layer 10, the insulating layer 20, and the second magneticlayer 30 experience the annealing at a high temperature for a sufficientperiod of time, the first and second magnetic layers 10 and 30 havingthe chemical formula of (A_(100-x)B_(x))_(100-y)C_(y) may be recoveredto the ordered crystal structure. In further detail, the annealing maybe performed for several minutes to several hours at a temperature of300° C. to 600° C. in order to prevent a deterioration of the magnetictunnel junction device due to the diffusion of elements.

By the annealing, the amorphous ferromagnetic materials in the first andsecond magnetic layers 10 and 30, are transformed to the ordered crystalstructure, and thereby obtain perpendicular magnetic anisotropy. Thatis, the magnetic tunnel junction device is manufactured by respectivelydepositing the first and second magnetic layers 10 and 30 in theamorphous phase and then the magnetic tunnel junction device is annealedaccording to the first exemplary embodiment of the present invention.Thus, by inducing perpendicular magnetic anisotropy of the first andsecond magnetic layers 10 and 30, the read signal value of the magnetictunnel junction device 100 can be increased and thermal stabilitythereof can be increased with a small volume. Accordingly, the firstmagnetic layer 10, the second magnetic layer 30, and the insulatinglayer 20 with materials in the magnetic tunnel junction device 100 canprovide the perpendicular magnetic anisotropy as well as excellentsignal characteristics.

FIG. 4 schematically shows a cross-sectional view of a magnetic tunneljunction device 200 according to a second exemplary embodiment of thepresent invention. The magnetic tunnel junction device 200 of FIG. 4 issimilar to the magnetic tunnel junction device 100 of FIG. 1, andtherefore like reference numerals designate like elements and detaileddescription thereof will be omitted.

As shown in FIG. 4, the magnetic tunnel junction device 200 includes afirst magnetic layer 10, an insulating layer 20, a second magnetic layer30, in-plane magnetic layers with in-plane anisotropy, 40 and 42, andseed layers, for inducing the formation of crystalline structure, 50 and52. The in-plane magnetic layers with in-plane anisotropy, 40 and 42,are used to compensate a large difference in crystal structure betweenthe magnetic layers 10 and 30 and the insulating layer 20. In addition,the in-plane magnetic layers with in-plane anisotropy, 40 and 42, may beused to increase a read signal value of the magnetic tunnel junctiondevice 200.

In this case, the insulating layer 20 is epitaxial to the in-planemagnetic layers with in-plane anisotropy, 40 and 42, and the firstmagnetic layer 10 and the second magnetic layer 30 are epitaxial to theseed layers 50 and 52. The first and second magnetic layers 10 and 30having perpendicular anisotropy is not epitaxial to the in-planemagnetic layers with in-plane anisotropy, 40 and 42, but they aremagnetically coupled thereto. Accordingly, the strong perpendicularanisotropy of the first and second magnetic layers 10 and 30 align themagnetic moments of the magnetic layer with in-plane anisotropy, 40 and42, into out-of-plane direction, so that a tunnel magnetoresistance withperpendicular magnetization can be realized in the magnetic tunneljunction device 200.

The in-plane magnetic layers with in-plane anisotropy, 40 and 42, have ahigh spin polarization, and the lattice constants thereof are slightlydifferent from that of the insulating layer 20. The in-plane magneticlayer with in-plane anisotropy, 40 and 42, may be formed of a materialsuch as Fe, CoFe, or CoFeB.

In addition, the seed layers 50 and 52 induces the formation ofcrystalline structure in the first and second magnetic layers 10 and 30,which obtain an ordered crystal structure through annealing withoutcontacting the insulating layer 20. For example, when the first magneticlayer 10 and the second magnetic layer 30 are formed of FePdB or FePtB,a seed layer 50 and 52 made of Pd, Pt, Au, or Fe is grown to have a(100) texture so as to induce the formation of an ordered crystallinestructure in FePdB or FePtB.

As described above, although the first and second magnetic layers 10 and30 and the insulating layer 20 are quite different from each other incrystal structure, the magnetic tunnel junction device 200 withperpendicular magnetization can be realized by using the in-planemagnetic layers with in-plane anisotropy, 40 and 42, and the seed layer,for inducing the formation of crystalline structures, 50 and 52.

FIG. 5 schematically shows a cross-sectional view of a magnetic tunneljunction device 300 according to a third exemplary embodiment of thepresent invention. The magnetic tunnel junction device 300 of FIG. 5 issimilar to the magnetic tunnel junction device 200 of FIG. 4, andtherefore like reference numerals designate like elements and detaileddescription thereof will be omitted.

As shown in FIG. 5, the magnetic tunnel junction device 300 includes afirst magnetic layer 10, an insulating layer 20, an in-plane magneticlayer with in-plane anisotropy 40, a seed layer 50 for inducing theformation of crystalline structure, an in-plane magnetic layer within-plane anisotropy 60, and a perpendicular magnetic layer 62 forinducing perpendicular magnetization.

A structure of the insulating layer 20 of the magnetic tunnel junctiondevice 300 of FIG. 5 is the same as that of the magnetic tunnel junctiondevice 200, excluding an upper structure thereof.

As shown in FIG. 5, the magnetic tunnel junction device 300 may use anamorphous material at one electrode and a crystalline material at theother electrode in order to induce perpendicular magnetic anisotropy.After annealing, the amorphous material becomes the first perpendicularmagnetic layer 10 and the crystalline material becomes the perpendicularmagnetic layer 62 for inducing perpendicular magnetization in anin-plane magnetic layer 60. In FIG. 5, an amorphous material below theinsulating layer 20 is used to induce perpendicular magnetization. Inthis case, the bottom electrode structure below the insulating layer 20is the same as that of the magnetic tunnel junction device of FIG. 4.

As shown in FIG. 5, the in-plane magnetic layer with in-plane anisotropy50 and the crystalline perpendicular magnetic layer 62 are formed on topof the insulating layer 20 in the magnetic tunnel junction device 300.For example, the in-plane magnetic layer with in-plane magneticanisotropy 50 may be formed of a CoFeB alloy, and the crystallineperpendicular magnetic layer 62 for inducing perpendicular magnetizationmay be formed of a multi-layered Co/Pt alloy.

Hereinafter, the present invention will be described in further detailthrough experimental examples. The experimental examples are provided asexamples of the present invention, and therefore the present inventionis not limited thereto.

Experimental Example 1

A magnetic tunnel junction device was manufactured by sequentiallystacking a magnetic layer, an insulating layer, and a magnetic layer.The magnetic layer was manufactured by adding 20 at % of boron to aFe₅₀Pd₅₀ alloy having 1:1 element composition. The Fe₅₀Pd₅₀ alloy had anordered crystal structure and perpendicular magnetic anisotropy. Themagnetic layer was amorphized by adding boron. The thickness of themagnetic layer was 3 nm.

Next, the insulating layer was deposited on the magnetic layer. Theinsulating layer was formed of magnesium oxide, and had a thickness of10 nm. The magnetic layer formed of (Fe₅₀Pd₅₀)₈₀B₂₀ was deposited on theinsulating layer.

FIG. 6 shows an X-ray diffraction graph of a magnetic tunnel junctiondevice manufactured according to Experimental Example 1.

As shown in FIG. 6, the X-ray diffraction peak was observed at alocation where 2θ is approximately 43°. This implies that MgO, that is,the insulating layer, was grown with a (001) orientation. Accordingly,it shows that the insulating layer was grown with a (001) orientation onthe magnetic layer. In addition, since the insulating layer wasdeposited on the amorphous magnetic layer, it is predicted that theroughness of the insulating layer would be low.

Experimental Example 2

A Pt layer was deposited at 40 nm to have a (001) orientation on an MgOsingle crystal substrate having a (001) orientation. Here, the Pt layerhad a thickness of 40 nm, and functioned as a seed layer for inducingthe formation of ordered crystalline structure in an amorphous magneticlayer. Next, a magnetic layer formed of (Fe₅₀Pd₅₀)₈₀B₂₀ was deposited inthe amorphous phase on the Pt layer. The thickness of the(Fe₅₀Pd₅₀)₈₀B₂₀ magnetic layer was 10 nm. The magnetic layer wasdeposited by sputtering and annealed for one hour at 500° C.

FIG. 7 shows a magnetic hysteresis curve of a magnetic layer of amagnetic tunnel junction device manufactured according to the secondexperimental example before annealing and after annealing. Here, themagnetic layer is formed of (Fe₅₀Pd₅₀)₈₀B₂₀. In FIG. 7, the thin lineshows a magnitude of perpendicular magnetization in the amorphous phasebefore annealing, and the thick line shows a magnitude of perpendicularmagnetization in the state that an ordered crystal structure isrecovered after annealing.

As shown in FIG. 7, the magnitude of perpendicular magnetization wasincreased in proportion to a magnetic field before the (Fe₅₀Pd₅₀)₈₀B₂₀magnetic layer is annealed, and the magnetization of the magnetic layerwas saturated around 7000 Oe which is a value of a demagnetization fieldoriginated from the shape anisotropy of the thin film. A saturationmagnetization of the (Fe₅₀Pd₅₀)₈₀B₂₀ magnetic layer was 560 emu/cc, andthe demagnetization field of the thin film was 7000 Oe. That is, becausethe magnetic layer formed of (Fe₅₀Pd₅₀)₈₀B₂₀ does not have a crystalstructure before the annealing, the magnetic layer had in-plane magneticanisotropy without having perpendicular magnetic anisotropy. However,after the magnetic layer formed of (Fe₅₀Pd₅₀)₈₀B₂₀ is annealed, themagnetization of the magnetic layer was saturated around 1000 Oe, whichis smaller than 7000 Oe. That is, the perpendicular magnetic anisotropywas obtained as the ordered crystal structure of the (Fe₅₀Pd₅₀)₈₀B₂₀magnetic layer was recovered after the annealing.

Although this invention has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments, but, by contrast, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

1. A magnetic tunnel junction device comprising: a first magnetic layerincluding a compound having a chemical formula of(A_(100-x)B_(x))_(100-y)C_(y); an insulating layer deposited on thefirst magnetic layer; and a second magnetic layer deposited on theinsulating layer and including a compound having a chemical formula of(A_(100-x)B_(x))_(100-y)C_(y), wherein the first and second magneticlayers have perpendicular magnetic anisotropy, and A and B are metalelements and C is at least one amorphizing element selected from a groupconsisting of boron (B), carbon (C), tantalum (Ta), and hafnium (Hf). 2.The magnetic tunnel junction device of claim 1, wherein A is at leastone element selected from a group consisting of iron (Fe), cobalt (Co),nickel (Ni), manganese (Mn), and chrome (Cr).
 3. The magnetic tunneljunction device of claim 2, wherein B is at least one element selectedfrom a group consisting of platinum (Pt), palladium (Pd), rhodium (Rh),gold (Au), mercury (Hg), and aluminum (Al).
 4. The magnetic tunneljunction device of claim 1, wherein the insulating layer includes acompound having a chemical formula of D_(100-z)E_(z), and D is at leastone element selected from a group consisting of lithium (Li), beryllium(Be), sodium (Na), magnesium (Mg), niobium (Nb), titanium (Ti), vanadium(V), tantalum (Ta), barium (Ba), palladium (Pd), zirconium (Zr), holmium(Ho), potassium (K), and silver (Ag), and E is at least one elementselected from a group consisting of oxygen (O), nitrogen (N), carbon(C), hydrogen (H), selenium (Se), chlorine (Cl), and fluorine (F). 5.The magnetic tunnel junction device of claim 1, wherein at least one ofthe first and second magnetic layers has a cubic or tetragonalstructure.
 6. The magnetic tunnel junction device of claim 1, furthercomprising: a first in-plane magnetic layer with in-plane magneticanisotropy deposited between the second magnetic layer and theinsulating layer; and a first seed layer, for inducing the formation ofcrystalline structure, deposited on the second magnetic layer.
 7. Themagnetic tunnel junction device of claim 6, wherein the first magneticlayer with in-plane magnetic anisotropy comprises at least one elementselected from a group consisting of Fe, CoFe, and CoFeB.
 8. The magnetictunnel junction device of claim 6, wherein when the compound included atleast one of the first and second magnetic layers has a chemical formulaof (Fe_(100-x)Pd_(x))_(100-x)B_(x) or (Fe_(100-x)Pt_(x))_(100-x)B_(x),the first seed layer for inducing the formation of crystalline structureincludes at least one element selected from a group consisting of Pd,Pt, Au, and Fe.
 9. The magnetic tunnel junction device of claim 6,further comprising: a second in-plane magnetic layer with in-planemagnetic anisotropy deposited between the first magnetic layer and theinsulating layer; and a second seed layer, for inducing the formation ofcrystalline structure, deposited under the first magnetic layer.
 10. Amagnetic tunnel junction, device comprising: a seed layer for inducingthe formation of crystalline structure; a magnetic layer withperpendicular magnetic anisotropy deposited on the seed layer andincluding a compound having a chemical formula of(A_(100-x)B_(x))_(100-y)C_(y); an in-plane magnetic layer with in-planemagnetic anisotropy deposited on the magnetic layer with perpendicularmagnetic anisotropy; an insulating layer deposited on the magnetic layerwith in-plane magnetic anisotropy; an in-plane magnetic layer within-plane magnetic anisotropy deposited on the insulating layer; and aperpendicular magnetic layer, for inducing perpendicular magneticanisotropy, deposited on the magnetic layer with in-plane magneticanisotropy, wherein A is at least one element selected from a groupconsisting of iron (Fe), cobalt (Co), nickel (Ni), manganese (Mn), andchrome (Cr), B is at least one element selected from a group consistingof platinum (Pt), palladium (Pd), rhodium (Rh), gold (Au), mercury (Hg),and aluminum (Al), and C is at least one element selected from a groupconsisting of boron (B), carbon (C), tantalum (Ta), and hafnium (Hf).11. A manufacturing method of a magnetic tunnel junction device (100),comprising: providing a first magnetic layer including an amorphizingelement; providing an insulating layer on the first magnetic layer;providing a second magnetic layer including an amorphizing element onthe insulating layer; and crystallizing the first and second magneticlayers by annealing on the first magnetic layer, the insulating layer,and the second magnetic layer.
 12. The manufacturing method of claim 11,wherein in the providing of the first magnetic layer and in theproviding of the second magnetic layer, the first and second magneticlayers respectively include a compound having a chemical formula of(A_(100-x)B_(x))_(100-y)C_(y), and A is at least one element selectedfrom a consisting of iron (Fe), cobalt (Co), nickel (Ni), manganese(Mn), and chrome (Cr), B is at least one element selected from a groupconsisting of platinum (Pt), palladium (Pd), rhodium (Rh), gold (Au),mercury (Hg), and aluminum (Al), and C is at least one amorphizingelement selected from a group consisting of boron (B), carbon (C),tantalum (Ta), and hafnium (Hf).
 13. The manufacturing method of claim11, wherein in the crystallizing of the first and second magneticlayers, the first and second magnetic layers have perpendicular magneticanisotropy.
 14. The manufacturing method of claim 11, wherein in thecrystallizing of the first and second magnetic layers, the annealing isperformed on the first magnetic layer, the insulating layer, and thesecond magnetic layer at 300° C. to 600° C.
 15. The manufacturing methodof claim 11, further comprising: providing an in-plane magnetic layerwith in-plane magnetic anisotropy between the second magnetic layer andthe insulating layer; and providing a seed layer on the second magneticlayer for inducing the formation of crystalline structure.
 16. Themanufacturing method of claim 15, further comprising: providing anothermagnetic layer with in-plane magnetic anisotropy between the firstmagnetic layer and the insulating layer; and providing a seed layerunder the first magnetic layer for inducing the formation of crystallinestructure.
 17. A manufacturing method of a magnetic tunnel junctiondevice, comprising: providing a seed layer for inducing the formation ofcrystalline structure; providing a magnetic layer including a compoundhaving a chemical formula of (A_(100-x)B_(x))_(100-y)C_(y) on the seedlayer; providing a first magnetic layer with in-plane magneticanisotropy on the magnetic layer; providing an insulating layer on thefirst magnetic layer with in-plane magnetic anisotropy; providing asecond magnetic layer with in-plane magnetic anisotropy on theinsulating layer; providing a perpendicular magnetic layer withperpendicular magnetic anisotropy on the second magnetic layer within-plane magnetic anisotropy; and crystallizing the magnetic layer byperforming annealing on the seed layer for inducing the formation ofcrystalline structure, the magnetic layer, the first magnetic layer within-plane magnetic anisotropy, the insulating layer, the second magneticlayer with in-plane magnetic anisotropy, and the perpendicular magneticlayer with perpendicular magnetic anisotropy, wherein, in thecrystallizing of the magnetic layer, the magnetic layer hasperpendicular magnetic anisotropy and includes a compound having achemical formula of (A_(100-x)B_(x))_(100-y)C_(y) in which A is at leastone element selected from a group consisting of iron (Fe), cobalt (Co),nickel (Ni), manganese (Mn), and chrome (Cr), B is at least one elementselected from a group consisting of platinum (Pt), palladium (Pd),rhodium (Rh), gold (Au), mercury (Hg), and aluminum (Al), and C is atleast one amorphizing element selected from a group consisting of boron(B), carbon (C), tantalum (Ta), and hafnium (Hf).